I have no idea if this is a good place to get questions about kubuntu answered, so I’m about to find out.
I’m switching from ubuntu to kubuntu after probably 20 years. Should have done it when Canonical switched to unity but at the time I seem to recall KDE 3 was only just out, so I put it off.
So… after years of things changing behind the scenes, I have no idea what the current login/session manager is. (gdm? ldm?) but I want one that matches my KDE desktop. What do I have to switch?
Cheers
Plasma uses SDDM as the login manager, so that would be installed by default in Kubuntu.
Changing the appearance would involve installing a new theme for it and/or setting a wallpaper, as well as using the “Apply Plasma Settings” option in System Settings.
Wallpaper iirc still needs to be located outside your $HOME. Many Global Themes pull in a matching SDDM theme, as well.
Excellent info @claydoh. I see sddm is indeed installed.
Googling, I find an article at linuxconfig dot org (n00bs can’t post links? wtf?) that leads me to try:
$ sudo systemctl disable gdm && sudo systemctl enable sddm
The article also suggests a ways to setup and test the theme.
Thank you
Are you adding Plasma to your existing Ubuntu install? Normally, that would give a prompt to select which login manager to use, ie replace GDM with SDDM. But that might depend on the meta-package you used to add plasma.
You can install it, as shown on linuxconfig:
sudo apt install sddm
Which would bring up the selection dialog, as shown on that page.
If you know it is installed and have more than one login manager installed, you can manually bring up the selection dialog like so :
sudo dpkg-reconfigure gdm3
Or
sudo dpkg-reconfigure sddm
You can check which one is in use like so:
systemctl status display-manager.service
However: if this is a normal Kubuntu install, you are already using SDDM so there is no action needed from you.
Also note that SDDM as a login manager is unrelated to the lock screen.
Now for testing, you may need to use a more distro-specific command, or a Plasma-version-specific one.
For Plasma 6 on *buntu:
sddm-greeter-qt6 --test-mode --theme /usr/share/sddm/themes/theme-name/
Substitute the full path to where you have the theme files if you have only downloaded the files.
Use sddm-greeter on *buntu 24.04 with Plasma 5.
..
This is fairly normal practice. I can’t recall the number of posts here, but 3 is a common minimum for drive-by spammer controls.
The way around it is to remove the “http” and “.” and break it up:
linuxconfig.org/how-to-customize-the-sddm-display-manager-on-linux
make it;
linuxconfig dot org/how-to-customize-the-sddm-display-manager-on-linux
That’s an epic answer my friend. Thank you. I’ve been delayed, but I’m getting back to this now.
I’ve had Kubuntu desktop installed side by side with Ubuntu forever. I’m finally making the jump. (After a couple of months I can say I prefer it. But there are a few paper cuts to solve…)
sddm was already installed. Your suggestion to reconfigure sddm did the trick.
Simply disabling gdm and enabling sddm didn’t seem to work, but I didn’t experiment much, just switched them back until today.
Actually, there is still an issue…
After booting I see an error dialog that reads ‘Configuration file “/var/lib/sddm/.config/sddm-greeterrc” not writable’
Google finds this Manjaro forum post forum.manjaro dot org/t/configuration-file-var-lib-sddm-config-sddm-greeterrc-not-writable/96109 which suggests to change the group/owner of .config to sddm
/var/lib/sddm exists for me and has owner:group sddm:sddm, but the .config dir it contains is owned by root. sddm should be able to write in there anyway.
Any thoughts?
I do not know. I don’t believe *buntu uses this directory for configuration files for SDDM itself, nor use a file called sddm-greeterrc as far as I can see. I do not have one anywhere I can find on any of my setups. All mentions of this error are for Arch or derivatives, and mostly before 2023.
Well, I changed the owner/group of everything in /var/lib/sddm. No error message logging in after a restart and it looks like some things actually were updated in there. Meh. There are bigger things to worry about.
Thanks for your help @claydoh